Furnace: Three (3) zone, 115 tons/hr pusher type reheat furnace operating at 2350˚F, processing rebar and merchant bar products.
Customer Need: To minimize/reduce excessive BTU loss in roof, sidewalls and skid pipe.
Engineered Approach: Using thermography and heat flow calculations, a hot face veneer was recommended to address BTU loss. The veneering design included:
High Temperature Energy Efficient Ceramic Coatings: ITC manufactures a proprietary, high temperature energy efficient ceramic (HTEEC) coating to work in concert with the furnace conditions and veneer design. Under ideal conditions, HTEEC coatings absorb energy from the process and re–radiate it to the furnace load, imparting the following benefits:
Lower Shell Temperatures – The combination of veneer and the coating significantly lowered shell temperatures.
Improved BTU Savings – Due to the thermal efficiencies, Btu savings were significantly better than the estimates.
Lower Operating Temperatures -The thermal efficiencies of the new design enabled the operators to drop normal furnace operating temperatures in the discharge zone.
ROOF, SIDEWALL & SKID PIPE THERMAL CALCULATIONS
Original Lining: 300˚ – 400˚F (calculated) – 330˚ – 430˚F (actual)
After Veneer/Coating: 250˚ – 350˚F (calculated) – 228˚ – 342˚F (actual)
BTU Savings: 50 MM BTU/hr (calculated) – 54.7 MM BTU/hr (actual)
BTU Savings Per Year = 54.77 MM Btu/hr x 24 hr/day x 208 days/yr x $4.05/MM Btu)
TOTAL IMPACT/YEAR = $1,230,000